In recent years, legged robots have been developed (Patent literatures 1 and 2). The control technique disclosed in Patent literature 1 generates gait patterns in which the angle of each joint is expressed as a time series so that the knee angular speed remains in a restricted range. Then, the motion of the robot is controlled in accordance with the gait patterns (for example, see Patent literature 1).
Further, the robot controller disclosed in Patent literature 2 controls the motion of a robot in such a manner that the measured upper body position, the measured posture trajectory, the measured foot position, the measured foot posture trajectory, the measured floor reaction point, and the measured floor reaction force converge to their target values (for example, see Patent literature 2).